Classical philosophy and Darwinian biology are far more compatible than is usually assumed. In fact, looking at either from the standpoint of the other can enrich and deepen our appreciation of both. From a Darwinian point of view, the theories of Plato and Aristotle deserve to be taken very seriously. From the classical point of view, Darwinian biology is much less reductionist than its enemies suppose.

Thursday, May 12, 2016

What is the human thing? 2

I have been reading Aristotle’s Categories tonight. I first read it as an undergraduate
philosophy major at the University of Arizona.
As always when I return to this master I am again astonished by the
power and durability of his thought. Twenty-three
centuries after his death, he continues to illuminate and be illuminated by the
efforts of those who try to become wise by asking one question after
another.

I confess that I did not know
until tonight that his word for categories is the same word that is frequently
used for an accusation. To categorize
someone, in common language Greek, was to accuse him of a crime. So to identify Donald Trump as a man is to
accuse him of something. This is the
sort of thing that Martin Heidegger would have written a whole,
incomprehensible book about.

The Categories begins with a basic fact about language. We use some words as homonyms, which sound
identical but mean entirely different things.
Think of baseball bat and
vampire bat. I got that example from a fellow grad student
Kevin Long. Sometimes we use words as
synonyms, as when we speak of sexually reproducing organisms and asexually reproducing organisms. Finally, we
sometimes use words as paronyms, as when we say that someone who does politics is a politician. That last term,
unfortunately, never made its way into English.

From that point of departure,
Aristotle dives deep into metaphysics.
Consider this statement: “the leaf on the tree is green”. Green is what we say about the leaf. The leaf is what we say green about. Aristotle uses that distinction as the basis
of what is more or less real. The things
that are most real are the things that are never said about anything else. We might say that a tree leafs out, but we
never say that this here tree “that here leafs”. The leaf is a real thing which can be green
and fresh or brown and withered. The
latter terms are meaningful and true only if they describe something real.

The term for real thing-ousia in the Greek-is usually translated
as substance, and for a very good
reason. The same words in both languages
indicate both a substratum that undergoes change (the iron that goes from black
and cold to red and hot in the blacksmith’s forge) and the property of a “man
of substance.” See note on Heidegger
above.

For Aristotle, the only genuine, “primary”
substances are individual things. His examples
are always organic: this here human being or this here horse. His real things are the real things in the
common sense meaning of the words, the things we can see and touch. Aristotle is presumably arguing with his
equally famous teacher, Plato, who taught that apparently more abstract things
like beauty, truth, and goodness were the real things.

Having made this point, Aristotle
immediately qualifies it in Plato’s direction.
He does so by making a distinction between primary substance (this here
horse) and secondary substances like horse
and animal. The latter are secondary (and hence not quite
genuine) substances because they can be said about something else. So one can say that Ken Blanchard is a human
being and an animal but one never says that this is a Ken Blanchard or that
this Ken Blanchards about anything but yours truly.

We do, however, speak about
species and genus (horse and animal in his examples) the same way that we speak
about individual creatures, as when Aristotle says that the human being is the
political animal. In this case, the human being is what political animal is said about. This gives Aristotle a way to stack the
candidates for genuine substance in order of reality. Species (horse) is more real than genus
(animal) because the latter can be meaningfully predicated of the former (a horse
is an animal), yet less real than Seabiscuit, which cannot be predicated of
anything.

The problems that Aristotle is
addressing here continue to haunt biology to this day. What is the biological substance? David Hull and Michael Ghiselin have argued
that a species is not a class but an individual. I am the particular person I am not because I
look like my father but because my mother and father begat me. Dogs are dogs not because they have this or
that definitive trait but because they were sired by other dogs.

While I don’t necessarily buy
into this, I think they are onto something.
Evolutionary biology fleshes out Aristotle’s thinking by extending it
backward into organic time. Organisms
branched off into plants and animals.
Animals split into distinct species.
Yet all of this depends, at every actual moment, on actual organisms, then
and there, surviving, being fruitful and multiplying. Aristotle’s candidates for substance are ranked
as they are in evolutionary history.
Pretty good for a guy who never looked into a microscope.

I will close this post with a
little quote from Aristotle (Categories sec. 5).

It seems that no substance is more or less [what it is]… I
mean that no substance can admit of degrees in itself. For example, the same substance, a man,
cannot be more or less a man as compared to another. One man cannot be more a man than another, in
the same way that one that one white thing can be whiter than another white
thing or one beautiful thing more beautiful than others.

Take that, my Southern
ancestors! Aristotle recognized, a good
two thousand years before Jefferson, that all men are created equal. Darwin may or may not have been motivated
towards his work by an opposition to slavery, in fact confirmed Aristotle’s
reasoning. No human being is more human
or whiter than another.